A STATISTICAL INVESTIGATION 501 



It may be that there is a segregation of gametes into two opposed 

 camps, as may perhaps take place in cases of typical Mendelian 

 inheritance. It may be that the two kinds of ova simply express 

 the fundamental alternatives in protoplasmic metabolism — 

 in the continual seesaw between anabolism and katabolism, that 

 the one kind of egg is relatively more anabolic than the other, 

 and that the interrelations between cytoplasm and nucleus are 

 thereby affected in such a way that in one case the potentialities 

 of a female organism find expression, while in another case the 

 potentialities of a male find expression. A physiological varia- 

 tion may serve as the liberating stimulus for the alternative 

 potentialities of the two sexes. 



§ 6. ^ Statistical Investigation. 



In regard to human offspring many attempts have been made 

 to discover the conditions which determine the sex. The 

 absolute and relative ages of the parents, their constitution and 

 state of health, their diet and conjugal habits, the relation of the 

 time of conception to the periods of menstruation, and so on, 

 have been referred to as possible causes. A certain number 

 of parents have some common characteristic, the ratio of males 

 and females in their offspring is compared with the average ratio, 

 and if the ratio is markedly different the conclusion is drawn 

 that the characteristic in question had some definite influence 

 upon the production of one sex or the other. 



Prof. Newcomb (1904) has made a welcome contribution to the 

 discussion by seeking statistically " to discover a criterion by 

 which we may distinguish between inequalities in the division 

 of a family between the two sexes which are simply the result of 

 chance and those which are the result of a unisexual tendency 

 on the part of the parents." He means by a unisexual tendency 

 some constitutional or other characteristic of the parents which 

 tends to the production mainly or wholly of male children, 

 or mainly or wholly of female children. 



